GHSA-43GX-6GV6-3JCP

Vulnerability from github – Published: 2026-03-02 20:14 – Updated: 2026-06-08 18:34
VLAI
Summary
Products.isurlinportal has possible open redirect when using more than 2 forward slashes
Details

Impact

A url /login?came_from=////evil.example may redirect to an external website after login.

Standard Plone is not affected, but if you have customised the login, for example with add-ons, you might be affected. You can try the url to check if you are affected or not.

Patches

The problem has been patched in Products.isurlinportal.

  • Plone 6.2: upgrade to Products.isurlinportal 4.0.0.
  • Plone 6.1: upgrade to Products.isurlinportal 3.1.0.
  • Plone 6.0: upgrade to Products.isurlinportal 2.1.0.
  • Older Plone versions don't have security support anymore.

Workarounds

There are no known workarounds.

Background

When you are anonymous and land on a page that requires a login, Plone sends you to the login form. After successful login, Plone redirects you back to the page you came from. Various other forms and pages have a similar system.

This could get abused by an attacker to trick Plone into redirecting to a different website. Plone checks the page that would be redirected to. It is only accepted if it is within the Plone site domain or part of a different trusted domain.

The main check for this is in the Products.isurlinportal package. A lot of potentially malicious urls are already safely rejected, but here a loop hole was found.

This was discovered during a penetration test by the CERT-EU Team.

Severity
5.3 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Show details on source website
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{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "Products.isurlinportal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.0.0a1"
            },
            {
              "fixed": "4.0.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.0.0a1"
      ]
    },
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "Products.isurlinportal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "3.0.0"
            },
            {
              "fixed": "3.1.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "Products.isurlinportal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.1.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "products-isurlinportal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.1.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "products-isurlinportal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "3.0.0"
            },
            {
              "fixed": "3.1.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-28413"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-601"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-02T20:14:23Z",
    "nvd_published_at": "2026-03-05T21:16:22Z",
    "severity": "MODERATE"
  },
  "details": "### Impact\nA url `/login?came_from=////evil.example` may redirect to an external website after login.\n\nStandard Plone is not affected, but if you have customised the login, for example with add-ons, you might be affected. You can try the url to check if you are affected or not.\n\n### Patches\nThe problem has been patched in `Products.isurlinportal`.\n\n* Plone 6.2: upgrade to `Products.isurlinportal` 4.0.0.\n* Plone 6.1: upgrade to `Products.isurlinportal` 3.1.0.\n* Plone 6.0: upgrade to `Products.isurlinportal` 2.1.0.\n* Older Plone versions don\u0027t have security support anymore.\n\n### Workarounds\nThere are no known workarounds.\n\n### Background\nWhen you are anonymous and land on a page that requires a login, Plone sends you to the login form. After successful login, Plone redirects you back to the page you came from.  Various other forms and pages have a similar system.\n\nThis could get abused by an attacker to trick Plone into redirecting to a different website. Plone checks the page that would be redirected to. It is only accepted if it is within the Plone site domain or part of a different trusted domain.\n\nThe main check for this is in the `Products.isurlinportal` package. A lot of potentially malicious urls are already safely rejected, but here a loop hole was found.\n\nThis was discovered during a penetration test by the CERT-EU Team.",
  "id": "GHSA-43gx-6gv6-3jcp",
  "modified": "2026-06-08T18:34:31Z",
  "published": "2026-03-02T20:14:23Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/plone/Products.isurlinportal/security/advisories/GHSA-43gx-6gv6-3jcp"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-28413"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/plone/Products.isurlinportal"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pypa/advisory-database/tree/main/vulns/products-isurlinportal/PYSEC-2026-112.yaml"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Products.isurlinportal has possible open redirect when using more than 2 forward slashes"
}



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